This invention relates to a text processing system such as electronic typewriter and word processor provided with a format information memory for storing plural sets of format information.
When printing a text with the electronic typewriter, it is generally required to specify print condition or format such as left and right margin positions, a line feed amount and a print pitch. Since it is bothersome to set up such format upon each printing, several different sets of format information are stored in memory in advance and a desired one is selected upon necessity so that a text is printed in accordance with the selected format information.
In an electronic control system disclosed in Japanese Patent Publication Sho No. 53-29500, there are stored in memory several different control programs such as whether the decimal point is to be printed, whether a number is to be punctuated with a comma at every third digit and whether the minus symbol is to be placed before or after the printed data. By combining these control programs as desired, plural sets of print format information may be set up and changed. In accordance with this prior art solution, however, it is very difficult and troublesome to develop an additional print condition other than those stored in the memory as control programs. A greater storage capacity is needed for one print format.
There has been provided an electronic typewriter incorporating a microcomputer, which includes RAM (random access memory) having a plurality of format information memories for storing different sets of format information and a work memory for reading out and changing the format information. In response to key operation, a specific format information can be read out from its format information memory and transferred to a work memory. The input data is printed in accordance with the format information stored in the work memory. This prior art electronic typewriter is, however, associated with a problem that it also requires the work memory to read out and change the format information stored in the format information memories, resulting in a greater storage capacity of RAM. Moreover, different keys have to be operated to read out a specific set of format information and also to store the changed format information.